This small swallow has a bright white belly, neck and cheek, with a white stripe extending up behind the eye. The head is green to brown and the back a shiny green or turquoise. The rump is a violet color, these brilliant hues resulting in the bird’s multicolored name. The wings are long and narrow and extend beyond the end of the 5-inch body and tail.

Violet green swallows forage on the wing, often higher than other swallows, where they take any flying insects, such as wasps, bees, flies, butterflies and moths. Habitat is widespread and generalized, including open pine and hardwood forests, urban areas, and even prairie lands where cavities for nesting can be found. The breeding range is in the western U.S. and Canada, extending into the Northwest Territories and most of Alaska. The limit of the U.S. range is far eastern New Mexico, the eastern plains of Colorado and along the eastern boundaries of Wyoming and Montana.

As secondary cavity nesters, they will use an old woodpecker hole or other den or cavity in a tree, rock cliff, birdhouse, or even cactus, in which to build their cup nest of plant matter often lined with feathers. In cliff settings large colonies may nest together. The single brood per year consists of four to six nestlings that are fed by both parents. Adults also continue to feed the fledglings after they leave the nest. Accounts of nesting cavity cooperation between V-G swallows and other species have been recorded, such as swallows feeding Western bluebird nestlings and later using the nest for their own brood after the bluebirds fledged. Competition for nesting cavities has also been observed between swallows and other earlier nesters, such as Hairy woodpeckers and Mountain chickadees. In each case the swallows were driven away and failed to take the nest site away from residents.

In cold conditions V-G swallows may enter a torpor-like state of inactivity in which they are unresponsive, but upon warming they slowly waken and are able to become animate and fly away. Violet-green swallows may also assume poses in which the wings and tail are briefly held facing the sun in an apparent bout of sunbathing. This behavior has been observed in birds after the nesting season when external parasites are abundant and the sunlight exposure is thought to mitigate the parasite infestation.

The Audubon Society reports that with continued global warming the range of the Violet-green swallow is expected to diminish along the periphery of the eastern and southern flanks, as well as in Alaska. The population is currently in a stable condition and the species is abundant.